[jQuery] Converting from Prototype...

I am trying to convert a site over from Prototyp to jQuery, and am
having some issue find an example of how to convert the below code.
Essentially all it does is allow you to request a url, it then updates
a span with the result of the link.
new Ajax.Updater('Span_To_update', 'URL',{asynchronous:true,
evalScripts:true }); return false;
Any help is appreciated. Thanks!